Preparation

Make the pot stickers

• Toss the cabbage and 1-1/2 tsp. salt in a large bowl. Set aside for 30 minutes. Transfer the cabbage to a clean kitchen towel or cheesecloth, gather the ends of the cloth together, and twist to squeeze as much water as possible from the cabbage (this will make the filling more cohesive). In another large bowl, combine the cabbage with the pork, scallions, garlic, tamari, sesame oil, and ginger.
• To fill the pot stickers, place about 1/2 Tbs. of the filling in the center of each wrapper. Avoid getting filling on the edges of the wrapper, which prevents proper sealing. Gently brush the edges with the beaten egg and fold each wrapper in half to form a half-moon shape. Starting at one end, fold and pinch the dough together to pleat; continue until the dumpling is sealed. Transfer the dumplings to a rimmed baking sheet, and cover with plastic wrap as they are completed.

Make the dipping sauce

• In a small bowl, combine the vinegar, soy sauce, sambal oelek, and oil, and mix well.

Cook and serve the pot stickers

• Heat a large nonstick skillet over high heat. Add the canola oil, and swirl to coat. When the oil shimmers, add the pot stickers in batches, flattened bottoms down, and cook without disturbing until golden brown, 1-1/2 to 2 minutes. Add about 1/2 cup water, and immediately cover to avoid spattering. Cook about 1 minute. Lift the cover and make sure about 1/8 inch of water remains in the pan; if not, add a bit more. Steam until the pot stickers are puffy and slightly translucent yet firm, and the water has evaporated, 3 to 5 minutes. If the water evaporates before the pot stickers are done, add more in 1/4-cup increments. If the pot stickers seem done, but water remains in the pan, drain the water from the pan, and return it to the stovetop. Continue to cook over high heat to allow the pot stickers to recrisp on the bottom, 1 to 3 minutes. Repeat with remaining batches. Transfer the pot stickers to a platter, and serve crisp side up, sprinkled with sesame seeds and with dipping sauce on the side.